Accidental activation of devices can be problematic. In one well-known example, cell phone calls can be unknowingly made while the cell phone is in a user's pocket or handbag. One technique to prevent accidental device activation is to include a lock/unlock feature on the phone. Typically, either a sequence of keystrokes or a personal pin number are used to unlock the phone.
Low-power mode is another feature of most mobile devices, particularly for mobile devices that depend on battery power. In order to activate a mobile device (i.e., exit low-power mode), generally multiple key strokes are needed. One example of a mobile phone with a low-power mode of operation is the Apple® Iphone®. That phone has a push button (separate from the touch screen) to activate the phone, but the button can be pushed unintentionally while the phone is in a pocket or in a handbag, draining battery power. Once the phone is activated, a separate operation is needed to unlock the phone.
It is desirable to make device activation and unlocking easier, while not loosing the benefits of low-power mode.